254 PRACTICAL ORGANIC CHEMISTRY PREPARATIONS 19—20. Glycocoll.—By the action of primary and secondary amines, corresponding amino-acids are formed. Chloracetic acid and methylamine yield sarcosine, xCl /NHCI-L CH2 + NH3CH8 = CH2 + HC1. \COOH \COOII The amino-acids are further obtained by the reduction (Zn and HC1) of nitro-, oximino- and cyano-acids, thus : CHo(N().2).COOII + 3Ha= CHa(NI Ia)COOII + 2li2O, CH3.C(NOli).COOH + 2llo = CH3.C1I(NH.,).COOII + HaO9 CN.COOH -h 2lL = CHo(NII.2).c6oH, and by the action of NH3 on the cyanhydrin of aldehydes and ketones, or simply of ammonium cyanide. The product is then hydrolysed with HC1, /CN / NH3 /CN CH3.CH H.,0 /COOII HCN CH3.COH •> CII3.CII \>H \Nl-Ia \NII, The amino-acids are crystalline compounds usually of a sweet taste and soluble in water. They are neutral compounds, from which it may be assumed that an inner ammonium salt is formed— /NH3 Nboo By the action of an acid chloride on the amino-acid, the hydro- gen of the amino-group may be replaced by an acicl radical. Hippuric acid has been synthesised in this way. yNHo ,NH.CO.CGH5 CH2 + C6H5COC1 = Clio + IIC1 . \coon XCOOH The amino-acids are not acted on by a hot solution of caustic alkali, but on fusion with caustic soda or potash, yield the amine and CO,,, /NH2 CH,.CH - CIL.CH2.NH2 \COOH CO2.